Effects of climate change and organic matter content on modelled active layer thickness and the thermal state of permafrost in Adventdalen, Svalbard

• Main Author: op den Kelder, Antonia
• Format: Bachelor Thesis
• Language: English
• Published: Stockholms universitet, Institutionen för naturgeografi 2017
• Subjects: Natural Sciences; Naturvetenskap; Physical Geography; Naturgeografi; Svalbard; Adventdalen; Active layer thickness; permafrost
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-147526

Climate change has already had an impact on the environment; this impact is expected to increase in the future. The Polar Regions are highly vulnerable to climate change because of polar amplification. Large amounts of carbon are stored in permafrost in the form of organic matter. Climate change and changes in land-use can destabilize these carbon reservoirs. This can lead to large emissions of greenhouse gasses to the atmosphere, and with that, increase the rate of climate change. It is crucial to know the effects of climate change on permafrost. This thesis uses the CoupModel5 to model the effects of climate change on the permafrost at the UNISCALM site, Adventdalen, Svalbard. Next to that, the effect of the presence of organic matter in relationship to climate change is investigated. High-resolution hydro-climatic data from the UNISCALM site is used as boundary conditions in the model set-up. The model is run for the period 1976-2013. The results are validated with sub-surface temperature data. After that, the same model set-up is used and the temperature is increased according to the temperature data from the Representative Concentration Pathways (RCPs) scenarios: RCP2.6,RCP4.5, RCP6.0, and RCP8.5, for the period 2014-2100. It is investigated how the thermal state of the permafrost and the active layer thickness (ALT) will be affected. Two alternate scenarios areinvestigated; (S2) 10 cm organic matter layer, and (S3) 50 cm organic matter layer. All RCPs show an increase in sub-surface temperature. For S1, until 2050 the RCPs follow a similar pattern, after that they start to diverge. RCP2.6 experiences only a slight increase until 2100. RCP4.5 and RCP6.0 are relatively similar until approximately 2080, from that point on the ALT from RCP6.0 plots consistently below RCP4.5. RCP8.5 shows a steady increase in temperature from 2050-2080. Around 2080 the permafrost starts to collapse and the permafrost degradation occurs rapidly. The different organic matter scenarios follow roughly the same pattern, but differ ...